Consequences in a softwood kraft pulp mill of initial high alkali concentration in the impregnation stage
Source abstract
Abstract
Abstract Impregnation with high initial concentration is fast and efficient, leading to a homogeneous delignification in the subsequent cook, resulting in improved screened pulp yield. To obtain high initial alkali concentration, the white liquor flow needs to be significantly increased. The moisture content of the wood chips and the alkali concentration of the white liquor limit the initial alkali concentration of the impregnation liquor that can be reached. It is therefore of interest to evaluate the possibility to implement high alkali impregnation (HAI) industrially and the consequences this would have on the mill system. The effect of HAI on mass and energy balances in a kraft pulp mill has been studied using mill model simulations. The sensitivity to disturbances in important parameters for process control has been compared to impregnation scenarios used industrially. It was shown that high initial alkali concentration can be achieved on industrial scale by increased white liquor flow. HAI has a positive effect on recovery flows and reduces the need for make-up chemicals. The HAI concept is less sensitive to variations in process parameters, such as chip moisture and white liquor concentration, thus diminishing the risk of alkali depletion in chip cores.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Lignin and Wood Chemistry · Advanced Mathematical Modeling in Engineering · Advanced Cellulose Research Studies
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
RISE Bioeconomy , Biorefinery and Energy , Box 5604 , Stockholm , Sweden
Funding
Svenska Forskningsrådet Formas
References (23)
Show source-provided references
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